1. Field of the Invention
The present invention relates to an optical apparatus having an image shake correcting function.
2. Description of the Related Art
In recent years, an image shake correcting function for correcting image shakes in a still image and a moving image has been required for an image pickup system using a lens. In order to realize the image shake correcting function, it is necessary to detect a vibration. For detecting the vibration, a method using an angular velocity sensor such as a gyrosensor is mainly employed. In general, the gyrosensor has structure which is likely to generate low-frequency noise. Even when no vibration is applied, an output of the gyrosensor disadvantageously fluctuates. Therefore, there arises a problem in that an image being picked up moves slowly because the image shake correction is performed even though no vibration is applied.
In order to solve the problem described above, a method of combining outputs of multiple angular velocity sensors having different characteristics to obtain an angular velocity, and a method of performing switching between multiple angular velocity sensors having different characteristics according to photographing modes for use have been proposed (Japanese Patent Application Laid-Open No. 2005-321726 and Japanese Patent Application Laid-Open No. 2006-292845).
According to the methods described in Japanese Patent Application Laid-Open No. 2005-321726 and No. 2006-292845, however, an image swinging amount generated when no vibration is applied (hereinafter, referred to simply as “image swinging amount”) is determined by an angular velocity sensor having the best noise characteristic among the multiple angular velocity sensors. Specifically, the image swinging amount cannot be further reduced by the above-mentioned methods in comparison with that in the case where a single angular velocity sensor having the best noise characteristic is used.